The present invention relates to integrated semiconductor device technology in the field of sensors and radiant sources of electromagnetic energy. More specifically, the present invention comprises an integrated semiconductor device which provides a new mirco environment for applications including sensing. The present semiconductor device, which may be fabricated through batch processing, provides an environment which permits a thermal-to-electric transducer or static electric element to be integrated with a semiconductor circuit chip while having substantially greater thermal and physical isolation from the chip than is possible with conventional emplacements of such components in integrated semiconductor devices. The present invention has applications in areas including flow sensing, detection of combustible gases, humidity sensing, and pressure sensing. However, the present invention is not limited to such applications.
The present invention comprises a semiconductor device and a method for fabricating the semiconductor device.
The semiconductor device comprises a semiconductor body having a depression formed into the first surface of the body. The device further comprises member means comprising a thermal-to-electric transducer or static electric element or electric to thermal element, the member means having a predetermined configuration suspended over the depression. The member means is connected to the first surface at least at one location, the depression opening to the first surface around at least a portion of the predetermined configuration, the depression providing substantial physical and thermal isolation between the element and the semiconductor body.
In this manner, an integrated semiconductor device provides an environment of substantial physical and thermal isolation between the transducer or element and the semiconductor body.
The method of making such a device comprises the steps of providing a semiconductor body with a first surface having a predetermined orientation with respect to a crystalline structure in the semiconductor body. The method further comprises applying a layer of material of which the member means is comprised onto the first surface. The method also comprises exposing at least one predetermined area of the first surface, the exposed surface area being bounded in part by the predetermined configuration to be suspended, the predetermined configuration being oriented so that undercutting of the predetermined configuration by an anisotropic etch will occur in a substantially minimum time. Finally, the method comprises applying the anisotropic etch to the exposed surface area to undercut the member means and create the depression.